Assertion 1 is correct. Assertion 2 and the answer to your two questions depends on the client and the type of hashing they use to determine which server to use. To understand this, check out the libketama consistent hash page<http://amarok.kde.org/blog/archives/363-libketama-a-consistent-hashing-algo-for-memcache-clients.html> .
On Fri, Mar 20, 2009 at 6:02 AM, Rachel <[email protected]> wrote: > > I'd just like to check that my understanding of how a distributed > memcached system works. Are these 2 assertions correct? > > 1) It's the client which is configured to know about multiple > memcached servers; the servers themselves know nothing about being > part of a cluster. > > 2) If you have one client configured to use servers A and B, and a 2nd > client configured to use servers A,B and C, the results will be > indeterminate. The clients may use the same servers for the same key, > or they may not - it's just a matter of chance. > > Questions: > > 1) Does the ordering of the servers matter in the client? If client 1 > uses server A and server B, while client 2 uses server B and server A, > will they hash the same? > > 2) Does the server name matter? If client 1 uses > name.memached.localnetwork and client 2 uses 192.168.0.1, will they > hash the same? > > Thanks > Rachel -- "If you see a whole thing - it seems that it's always beautiful. Planets, lives... But up close a world's all dirt and rocks. And day to day, life's a hard job, you get tired, you lose the pattern." Ursula K. Le Guin http://www.finsel.com/words,-words,-words.aspx (My blog) - http://www.finsel.com/photo-gallery.aspx (My Photogallery) - http://www.reluctantdba.com/dbas-and-programmers/blog.aspx (My Professional Blog)
